6U7-G as driver in a RH 807?

[aardvarkash10]

Nice looking tube (yeah, form over function is not a good starting point, but hey...) that mimics the shape of the 807. Some NOS items listed here in NZ at a reasonable price, so would make an easy option.

Specs here - http://www.mif.pg.gda.pl/homepages/f...049/6/6U7G.pdf

Thanks all!

[Miles Prower]

Originally Posted by aardvarkash10

Nice looking tube (yeah, form over function is not a good starting point, but hey...) that mimics the shape of the 807. Some NOS items listed here in NZ at a reasonable price, so would make an easy option.

From the spec sheet: "triple grid, super-control amplifier". That's an old timey way to say "variable-u". This is not a good thing, and the plate characteristics look hideously nonlinear. The 6U7 was obviously designed for use as a grid biased controlled IF amp for superhet xcvrs. In that case, they didn't care about linearity since the harmonic distortion is filtered out with double tuned IF interstage xfmrs.

Might be useful if you triode it?

[aardvarkash10]

I kinda figured that since they were available, they must be unusable, but sooner or later I must strike it lucky! Triode? Yeah, but defeats the purpose of a pentode driver for the RH807... Still, if I was any sort of adventurer, I should give it a try anyway - in the spirit of constant learning.

Cheers!

[Shoog]

Essentially I agree with Miles. There are far better candidates out there.

Having said that, looking at the curve given it looks as if biasing at -5V might just be workable. assuming an input signal of 2v it shouldn't stray outside it linear range to much. If its not to much trouble you could breadboard it up and see if it works.

Shoog

[aardvarkash10]

Originally Posted by Shoog

Essentially I agree with Miles. There are far better candidates out there....Shoog

Sonically and electrically, you are both probably right. But like the mechanical gob-fest that was the Renault Alpine GTA, this thing is pretty!

Thanks guys - wiser heads and all that.